--# selene: allow(unused_variable)
---@diagnostic disable: unused-local
local ls = require("luasnip")
-- some shorthands...
local s = ls.snippet
local sn = ls.snippet_node
local t = ls.text_node
local i = ls.insert_node
local f = ls.function_node
local c = ls.choice_node
local d = ls.dynamic_node
local r = ls.restore_node
local l = require("luasnip.extras").lambda
local rep = require("luasnip.extras").rep
local p = require("luasnip.extras").partial
local m = require("luasnip.extras").match
local n = require("luasnip.extras").nonempty
local dl = require("luasnip.extras").dynamic_lambda
local fmt = require("luasnip.extras.fmt").fmt
local fmta = require("luasnip.extras.fmt").fmta
local types = require("luasnip.util.types")
local conds = require("luasnip.extras.conditions.expand")

-- complicated function for dynamicNode.
local function jdocsnip(args, _, old_state)
	-- !!! old_state is used to preserve user-input here. DON'T DO IT THAT WAY!
	-- Using a restoreNode instead is much easier.
	-- View this only as an example on how old_state functions.
	local nodes = { t({ "/**", " * " }), i(1, "A short Description"), t({ "", "" }) }

	-- These will be merged with the snippet; that way, should the snippet be updated,
	-- some user input eg. text can be referred to in the new snippet.
	local param_nodes = {}

	if old_state then
		nodes[2] = i(1, old_state.descr:get_text())
	end
	param_nodes.descr = nodes[2]

	-- At least one param.
	if string.find(args[2][1], ", ") then
		vim.list_extend(nodes, { t({ " * ", "" }) })
	end

	local insert = 2
	for indx, arg in ipairs(vim.split(args[2][1], ", ", true)) do
		-- Get actual name parameter.
		arg = vim.split(arg, " ", true)[2]
		if arg then
			local inode
			-- if there was some text in this parameter, use it as static_text for this new snippet.
			if old_state and old_state[arg] then
				inode = i(insert, old_state["arg" .. arg]:get_text())
			else
				inode = i(insert)
			end
			vim.list_extend(nodes, { t({ " * @param " .. arg .. " " }), inode, t({ "", "" }) })
			param_nodes["arg" .. arg] = inode

			insert = insert + 1
		end
	end

	if args[1][1] ~= "void" then
		local inode
		if old_state and old_state.ret then
			inode = i(insert, old_state.ret:get_text())
		else
			inode = i(insert)
		end

		vim.list_extend(nodes, { t({ " * ", " * @return " }), inode, t({ "", "" }) })
		param_nodes.ret = inode
		insert = insert + 1
	end

	if vim.tbl_count(args[3]) ~= 1 then
		local exc = string.gsub(args[3][2], " throws ", "")
		local ins
		if old_state and old_state.ex then
			ins = i(insert, old_state.ex:get_text())
		else
			ins = i(insert)
		end
		vim.list_extend(nodes, { t({ " * ", " * @throws " .. exc .. " " }), ins, t({ "", "" }) })
		param_nodes.ex = ins
		insert = insert + 1
	end

	vim.list_extend(nodes, { t({ " */" }) })

	local snip = sn(nil, nodes)
	-- Error on attempting overwrite.
	snip.old_state = param_nodes
	return snip
end

return {
	-- Very long example for a java class.
	s("fn", {
		d(6, jdocsnip, { 2, 4, 5 }, {}),
		t({ "", "" }),
		c(1, { t("public "), t("private ") }),
		c(2, { t("void"), t("String"), t("char"), t("int"), t("double"), t("boolean"), i(nil, "") }),
		t(" "),
		i(3, "myFunc"),
		t("("),
		i(4),
		t(")"),
		c(5, { t(""), sn(nil, { t({ "", " throws " }), i(1) }) }),
		t({ " {", "\t" }),
		i(0),
		t({ "", "}" }),
	}),
}
